The invention relates to an amplifier arrangement comprising a first amplifier section having an input and an output, a second amplifier section having an input which is connected to the output of the first amplifier section, an output, at least a first output transistor and a first driver transistor which drives said output transistor, and a protection circuit for overload protection of said output transistor. Such amplifier arrangements are used for example as integrated power amplifiers for audio signals. The output transistors of such amplifiers must be protected against voltage and/or current overloading or overloading by a combination of voltage and current (so-called SOAR protection).
Amplifier arrangements of the type set forth above are known inter alia from DE-PS 18.11.765 and the magazine "Neues aus der Technik", no. 3, 01-07-1977, page 4, publication no. 406.
In these amplifier arrangements the protection circuit has a low gain because the protection acts on the bae of the output transistor. However, this low gain has the drawback that the protection circuit may introduce distortion when this circuit is not activated. This problem cannot readily be solved by increasing the gain factor of the protection circuit because this may give rise to instabilities when the protection circuit is in the activated condition.